1. Field of the Invention
The present invention relates to systems for processing data from patients undergoing cardiovascular procedures, e.g. electrophysiology (EP) procedures.
2. Description of the Related Art
Patients with abnormal cardiac rhythms can be treated with EP, or receive an implanted device (ID), such as a pacemaker or implantable cardioverter-defibrillator (ICD). These therapies and devices are effective in restoring the patient's cardiac rhythm to a normal level, and are typically characterized by a collection of data-generating devices that are used before, during, and after procedures for EP or the ID.
Prior to such a procedure, physicians often prescribe electrocardiography (ECG) monitors that measure time-dependent waveforms, from which heart rate (HR) and information related to arrhythmias and other cardiac properties are extracted. These systems can characterize ambulatory patients over short periods (e.g. 24-48 hours) using ‘holier’ monitors, or over longer periods (e.g. 1-3 weeks) using cardiac event monitors. Conventional holter or event monitors typically include a collection of chest-worn ECG electrodes (typically 3 or 5), an ECG circuit that collects analog signals from the ECG electrodes and coverts these into multi-lead ECG waveforms, and a computer processing unit that analyzes the ECG waveforms to determine cardiac information. Typically the patient wears the entire system on their body. Some modern ECG-monitoring systems include wireless capabilities that transmit ECG waveforms and other numerical data through a cellular interface to an Internet-based system, where they are further analyzed to generate, for example, reports describing the patient's cardiac rhythm. In less sophisticated systems, the ECG-monitoring system is worn by the patient, and then returned to a company that downloads all relevant information into a computer, which then analyzes it to generate the report. The report, for example, may be imported into the patient's electronic medical record (EMR). The EMR avails the report to cardiologists or other clinicians, who then use it to help characterize the patient.
To monitor non-ambulatory, hospitalized patients, conventional vital sign monitors include ECG monitoring systems that characterize a patient's cardiac response in a similar way to holter or event monitors. Such monitors typically measure multi-lead ECG waveforms that are processed by embedded software within the monitor to generate ECG waveforms and determine HR and a wide range of other cardiac properties.
During a conventional EP procedure, software systems can collect physiological information from the patient (e.g. vital signs and ECG waveforms), which is then used to help guide the procedure. These data are also stored in the patient's EMR, where they can be used for future analysis by cardiologists and other clinicians. ECG systems used during EP procedures typically measure 12 leads of ECG waveforms, which a cardiologist then interprets to elucidate, diagnose, and ultimately treat the electrical activities of the patient's heart. Additionally, during EP, an invasive catheter records spontaneous activity of the heart, as well as cardiac responses to programmed electrical stimulation (PES). In addition to these diagnostic and prognostic procedures, an EP cardiologist uses therapeutic methods, such as radio frequency ablation of pre-determined portions of the heart, to adjust the patient's cardiac rhythm to a relatively stable state. ECG-monitoring devices used in the EP procedure measure the response of the injured or cardiomyopathic myocardium to PES on specific pharmacological regimens in order to assess the likelihood that the regimen will successfully prevent potentially fatal sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) in the future. Sometimes a series of drug trials are conducted before and/or after an EP procedure to enable the cardiologist to select a regimen for long-term treatment that best prevents or slows the development of VT or VF following PES. Other therapeutic modalities employed in this field include antiarrhythmic drug therapy and IDs. Such studies may also be conducted in the presence of a newly deployed ID.
Modern IDs also include electronic circuitry for recording and storing cardiac parameters, such as arrhythmia information, HR, HR variability, and data describing the performance of the implanted device. Typically the ID stores this information within a computer memory that can be interrogated over a short-range wireless interface by a specialized device within a cardiologist's office called a ‘programmer’. Both the programmer and ID are typically designed and manufactured by the same company. Medtronic, the world's largest manufacturer of IDs, also makes a software system called ‘Paceart’ that receives, stores, and displays scheduling information and data generated by all major manufacturers of IDs, e.g. Medtronic, Boston Scientific, St. Jude, and Biotronix. The programmer typically includes a computer, display, ECG-measuring system, thermal printer, and a wand that is placed over the implanted device to read information over a short-range, wireless interface. Once read, the computer stores information generated by the ID, and at a later time can import this information into the patient's EMR, where it can be used to further diagnose the patient.
Many conventional EMRs are large software systems hosted on computer servers within a hospital or medical clinic. Some EMRs reside in ‘the cloud’, meaning they are hosted on remote, Internet-connected computer servers (located, e.g., in a third-party data center), which then render a graphical user interface (GUI) to hospital clinicians with a conventional web browser. In most instances, hospital administrators and clinicians use either the EMR or a secondary software system to perform ancillary functions related to the EP procedure, such as scheduling, billing, and patient follow-up.